We started getting a preg_match Visual Composer PHP error that was: Warning: preg_match() expects parameter 2 to be string, array given in /wp-content/themes/bridge/vc_templates/vc_empty_space.php on line 12.
I was able to determine that when using the empty space feature for managing site contents in the design, if you saved “px” in the pixel value for the size of the empty space, WordPress results would throw this error. For example, if I saved 16px for the size, we would get this error message. However, if I went back in and just saved the value as 16 the system would work as expected.
This is only a slight fix, I have discovered that in a recent update to Visual Composer, the issue was resolved. So be sure you have updated to (at this time) v4.8
Here is a quick link to the Visual Composer plugin.
Their is a Multiple XSS Vulnerability Update For WP Bakery Visual Composer that was released today. This is a free update from WP Bakery. I have not been able to find the details of the XSS vulnerabilities discovered and patched but I have one client with an older version of the Visual Composer that has been hacked a few times. I suspected this was the culprit and now we have an update for it.
The update is a free download from Code Canyon. Performing the update is easy if you have FTP, just download, extract, and copy over the existing folder /js_composer folder in your WordPress plugins.
If you don’t have FTP access you should be able to upload the .zip file via the plugin updater in the WordPress plugin area.